Nitrous decomposition without catalyst

ABSTRACT

A method for nitrous decomposition can include: expanding liquid nitrous into gaseous nitrous in a decomposition chamber; injecting heated nitrogen gas into the decomposition chamber so as to mix with the gaseous nitrous, wherein the heated nitrogen gas is at a nitrous decomposition temperature; heating the gaseous nitrous with the heated nitrogen gas to the nitrous decomposition temperature; and decomposing the gaseous nitrous into nitrogen and oxygen. The method can include: heating the nitrogen to at least the nitrous decomposition temperature; heating the liquid nitrous prior to expansion into the decomposition chamber; and performing the decomposition without a catalyst or heating element in the decomposition chamber. A swirling device can be positioned at an inlet to the decomposition chamber. A swirling nozzle can be positioned at an inlet to the decomposition chamber.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application claims priority to U.S. Provisional Application No. 63/092,280 filed Oct. 15, 2020, which provisional is incorporated herein by specific reference in its entirety.

BACKGROUND Field

The present disclosure relates to a system for nitrous decomposition without a catalyst. The nitrous decomposition can provide constituents of heated air to a nozzle (e.g., converging-diverging nozzle) to create high velocity conditions (i.e. high Mach number) of a test cell, or hereafter called a “wind tunnel” system.

Description of Related Art

Previously, high airspeed test facilities have used various means for producing a working fluid to pass over a test object at high velocities, which can be used to simulate the flight of the test object through the atmosphere. The working fluid can be the simulated “air” in a wind tunnel, which is produced by various means of obtaining a high velocity gas. The prior approaches include using a thermal gas (and its inherent thermal capacity) that is obtained from combustion air heating (e.g., done in current facilities such as the Arnold Engineering Development Center's (AEDC) Aerodynamic Propulsion Test Unit (APTU)), electrical arc-jet air heating, or others. The working fluid can be used in high speed/hypersonic (HS/H) device test facilitates. However, working fluid that is not clean “air” can produce improper test conditions, which are not commensurate with actual flight conditions experienced by a test object, such as an HS/H device (e.g., a plane, spacecraft, missile, or other flying object). The improper test conditions that result from an inadequate working fluid can lead to errors in the design of HS/H devices. There are challenges with providing test conditions that are commensurate with actual flight conditions experienced by an HS/H device.

Prior working fluids have been vitiated air, which is unfavorable. Vitiated air is not fresh or clean and often includes the contaminates that result from its generation. Contaminants of vitiated air include: too much water vapor, such as in the form of steam (and resultant HxOy radicals); free radical species (e.g., from vitiation-combustion preheaters), such as H, O, and OH when H₂ fuel is used, and also CxHyOz radicals when hydrocarbons (HC) are used; nitric oxides, such as NO that can be produced in amounts of 0.3 to 3 mole percent, which can exert particularly strong effects on low-temperature ignition and flame holding processes; excessive CO₂; metallic/condensed-oxide species in the airstreams; and charged and electronically excited molecular species. Therefore, non-vitiated air is desirable.

Additionally, non-vitiated air has been provided as an improvement; however, the prior non-vitiated air still can be problematic due to the modes of generation. The phrase “non-vitiated air” as used herein refers to a gas composition that is substantially free of contaminates (e.g., carbon-based particulate) and comprises a composition substantially similar to atmospheric air. In general, it has been found that vitiation contamination has a profound effect on vibrational relaxation, combustion kinetics, condensation and overall test engine performance. The non-vitiated air can be substantially similar to atmospheric air. The non-vitiated air can be obtained by nitrous oxide decomposition, such as a catalytic decomposition, a shock decomposition, a combustion decomposition, or combinations thereof. The decomposition can be as generally known (e.g., as discussed in: “Modeling of N2O Decomposition Events” by Arif Karabeyoglu, Jonny Dyer, Jose Stevens, and Brian Cantwell. 44th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit, Joint Propulsion Conferences; U.S. Pat. No. 6,779,335 to Herdy; and/or U.S. Pat. No. 9,598,323 to Herdy, which are all hereby incorporated by reference).

Current high speed/hypersonic (HS/H) device test systems can be expensive to operate and produce improper test conditions that are not commensurate with actual conditions experienced by an HS/H device. The improper test conditions can lead to errors in the design of HS/H devices. There are challenges with providing test conditions that are commensurate with actual flight conditions experienced by an HS/H device. As a result, improved wind tunnels can include nozzles that accelerate the working fluid to provide realistic testing conditions. Converging-diverging (CD) nozzles can provide realistic testing conditions as far as airflow is concerned, but are set in dimension, which results in very limited flowrate modulation from changes to the system in features other than nozzle throat.

Thus, there is a need for improved systems for producing simulated non-vitiated air for use in wind tunnels, such as those with CD nozzles, to a achieve a wider range of Mach numbers to provide realistic testing conditions.

SUMMARY

In some embodiments, a method for nitrous decomposition can include: expanding liquid nitrous into gaseous nitrous in a decomposition chamber; injecting heated nitrogen gas into the decomposition chamber so as to mix with the gaseous nitrous, wherein the heated nitrogen gas is at a nitrous decomposition temperature; heating the gaseous nitrous with the heated nitrogen gas to the nitrous decomposition temperature; and decomposing the gaseous nitrous into nitrogen and oxygen. In some aspects, the method can include heating the nitrogen to at least the nitrous decomposition temperature, which is at least about 900, 1200 or 1300 degrees K. In some aspects, the method can include heating the liquid nitrous prior to expansion into the decomposition chamber. In some aspects, the method can include performing the decomposition without a catalyst or heating element in the decomposition chamber. In some aspects, a mixing apparatus is used for mixing the gaseous nitrous and heated nitrogen gas in the decomposition chamber.

In some embodiments, the method of nitrous decomposition can include swirling the gaseous nitrous and heated nitrogen gas together with a swirling device. In some aspects, the swirling can include passing the heated nitrogen gas through a swirling device to cause the heated nitrogen gas to swirl with the nitrous gas. In some aspects, the swirling can include passing the liquid nitrous through a swirling nozzle for expanding the liquid nitrous into the gaseous nitrous to cause the gaseous nitrous to swirl with the heated nitrogen gas.

In some embodiments, a nitrous decomposition system can include: a liquid nitrous supply system; a heated nitrogen supply system configured to provide heated nitrogen gas at a nitrous decomposition temperature; and a decomposition reactor. The decomposition reactor can include: a decomposition chamber having a reaction region and an outlet; a liquid nitrous nozzle configured to expand the liquid nitrous into gaseous nitrous in the decomposition chamber; and a heated nitrogen nozzle configured to inject heated nitrogen gas into the decomposition chamber so as to mix with the gaseous nitrous. In some aspects, the decomposition reactor is configured to: heat the gaseous nitrous with the heated nitrogen gas to the nitrous decomposition temperature; and decompose the gaseous nitrous into nitrogen gas and oxygen gas. In some aspects, the heated nitrogen system includes at least one heater for heating the nitrogen to at least the nitrous decomposition temperature, which is at least about 1300 degrees K. In some aspects, the liquid nitrous supply system includes at least one heater for heating the liquid nitrous prior to expansion into the decomposition chamber. In some aspects, the decomposition chamber is devoid of a catalyst or heating element therein. In some aspects, the system includes a mixing device configured for mixing the gaseous nitrous and heated nitrogen gas in the decomposition chamber.

In some embodiments, the system includes a swirling device that is positioned and configured for swirling the gaseous nitrous and heated nitrogen gas together. In some aspects, the swirling device is positioned at an inlet to the decomposition chamber, such that the heated nitrogen gas is passed through the swirling device to cause the heated nitrogen gas to swirl with the nitrous gas. In some aspects, a swirling nozzle is positioned at an inlet to the decomposition chamber, such that the liquid nitrous is passed through the swirling nozzle for expanding the liquid nitrous into the gaseous nitrous to cause the gaseous nitrous to swirl with the heated nitrogen gas.

In some embodiments, a wind tunnel system can include any embodiment of a nitrous decomposition system. The wind tunnel system can also include a variable converging-diverging nozzle having an inlet that is fluidly coupled with the outlet of the decomposition chamber.

In some embodiments, a method for operating a wind tunnel can include: expanding liquid nitrous into gaseous nitrous in a decomposition chamber; injecting heated nitrogen gas into the decomposition chamber so as to heat the gaseous nitrous, wherein the heated nitrogen gas is at a nitrous decomposition temperature; heating the gaseous nitrous with the heated nitrogen gas to the nitrous decomposition temperature; decomposing the gaseous nitrous into nitrogen and oxygen as simulated air; and passing the simulated air through a nozzle into a wind tunnel containing a test object that receives the simulated air.

In some embodiments, a wind tunnel can include the CD nozzle of one of the embodiments. The wind tunnel can also include a test gas supply, such as from nitrous decomposition, fluidly coupled with the inlet opening of the nozzle. A test cell/chamber can be provided that has at least a portion of the nozzle therein. An exhaust outlet is fluidly coupled with the outlet opening of the nozzle with a test region within the test cell between the outlet opening and exhaust diffuser. In some aspects, the gas supply includes a gas generation system, which can be the nitrous decomposition system. In some aspects, the gas generation system is configured for decomposing nitrous oxide without a catalyst to generate heat and obtain a Mach number of gas flow in the nozzle.

In some embodiments, a method of testing an object can use a wind tunnel with a variable CD nozzle in accordance with an embodiment provided herein. The method can include placing a test object in the test region of the test cell. Then, the CD nozzle can receive a test gas from decomposed nitrous and pass the test gas from the outlet opening of the nozzle onto the test object. The method can also include operating the system for changing the shape of the flexible body to change the dimension or the location of the throat plane relative to at least one of the inlet plane or outlet plane to change at least one property of the test gas at the test object.

The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF THE FIGURES

The foregoing and following information as well as other features of this disclosure will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only several embodiments in accordance with the disclosure and are, therefore, not to be considered limiting of its scope, the disclosure will be described with additional specificity and detail through use of the accompanying drawings.

FIG. 1 illustrates an embodiment of a wind tunnel system that generates high velocity air by nitrous decomposition without a catalyst.

FIG. 2 illustrates an embodiment of a catalystless nitrous decomposition system.

FIG. 3A illustrates an embodiment of a nitrous decomposition nozzle having an outer tube with an inner tube concentrically contained therein.

FIG. 3B shows the spray decomposition in the reaction chamber of FIG. 3A, which provides for swirling fluid flow with recirculation flows.

FIG. 3C illustrates an embodiment of a decomposition nozzle that further includes turning vanes positioned throughout the outer tube.

FIG. 3D illustrates an embodiment of a decomposition nozzle that includes turning vanes that have a curved shape that curve the flow direction to enhance turbulence and mixing between the nitrogen and nitrous.

FIG. 3E s illustrates an embodiment of a decomposition nozzle that further includes turning vanes in a staggered placement to form a tortuous pathway which results in mixing of the nitrogen and nitrous.

FIG. 4A includes a graph that shows the oxygen (O₂) mass fraction stabilizing after about 0.9 seconds of dissociation.

FIG. 4B includes temperature profile data that shows the temperature in Kelvin with the nitrogen being heated to above 1600 degrees K, and the liquid nitrous isotropically expanding into the turning vane and quickly increasing temperature to 1600 degrees K from mixing with the heated nitrogen.

FIG. 4C includes a graph that shows the oxygen mass fraction over time for different pressures, where the higher pressures above 250 psi, especially above 350 psi, and especially above 384 psi appear to enhance nitrous decomposition.

FIG. 4D includes the temperature profile data obtained for the different pressures of FIG. 4C.

FIG. 4E includes a graph that shows the oxygen mass fraction over time for different temperatures, where the higher temperatures above 1300 degrees K, especially above 1400 degrees K, and especially above 1600 degrees K appear to enhance nitrous decomposition.

FIG. 4F includes the temperature profile data obtained for the different temperatures of FIG. 4E.

FIG. 5 illustrates an embodiment of the nozzle system that has the variable CD nozzle.

FIG. 6 illustrates an example computing device (e.g., a computer used as controller) that may be arranged in some embodiments to perform the control of the nitrous system, nitrogen system, decomposition system, a variable CD nozzle system and operational methods (or portions thereof) as described herein.

FIG. 7A includes a schematic depiction of swirl stabilized nitrous dissociation that utilizes liquid or gaseous nitrous injection encapsulated by pre-heated and swirled nitrogen.

FIG. 7B includes a graph showing the use of the swirled nitrogen circumferential component (e.g., swirler) within each injection assembly improves nitrous/nitrogen dissociation stability via recirculation and injector-to-injector communication via greater flame spreading.

FIG. 7C includes an image of a simulation to demonstrate the potential of high swirl number nitrogen injection to improve stability and communication.

FIG. 8 includes images of testing that shows a current nitrous oxide/nitrogen atomizer and vaporization device, where “cold” nitrous oxide is injected as droplets via a droplet generation device (e.g., Schlick model 556 simplex atomizer) with the intent to vaporize the nitrous oxide into a nitrogen slip steam (i.e., annular surrounding) nitrogen gas.

FIG. 9A shows an embodiment of a decomposition reactor that receives the nitrous in a nitrous inlet and heated nitrogen in a nitrogen inlet into a decomposition chamber for decomposition into nitrogen and oxygen, where a swirler nozzle system is used to swirl the nitrous and nitrogen.

FIG. 9B shows an embodiment of the swirler nozzle system, which includes the swirler having the central orifice and swirling concentric orifice.

FIG. 9C shows an embodiment of the swirler without the lumen walls of the swirling conduit.

FIG. 9D shows an embodiment of the swirler nozzle having the central conduit and swirling concentric conduit, with orifices defined by the space between each swirling member.

FIG. 10A shows an embodiment of the swirler having the swirl nozzle in the central orifice, where the swirl nozzle is shown with four swirl nozzle openings.

FIG. 10B shows an embodiment of the swirl nozzle inlet side, which shows the swirl nozzle conduits.

FIG. 10C shows an embodiment of the swirl nozzle outlet side that sprays from the swirl nozzle openings into the reaction chamber.

FIG. 10D shows the swirl nozzle conduits extending from the middle on the inlet side outwardly to the swirl nozzle openings on the outlet side.

The elements and components in the figures can be arranged in accordance with at least one of the embodiments described herein, and which arrangement may be modified in accordance with the disclosure provided herein by one of ordinary skill in the art.

DETAILED DESCRIPTION

In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented herein. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, separated, and designed in a wide variety of different configurations, all of which are explicitly contemplated herein.

Generally, the present invention relates to a system for catalystless nitrous decomposition, which generates nitrogen (N₂) and oxygen (O₂) at high velocity for use in a hot air wind tunnel (HAT) system. The nitrous decomposition is performed without a catalyst, which is a significant improvement in design. The HAT provides sufficient hypersonic test laboratory science and technology infrastructure to support testing of aerodynamics in a simulated environment. The HAT can employ various components for aerodynamics testing in high velocity simulated air, which contributes to enhanced performance. The HAT can provide the high velocity air to a nozzle for increasing the velocity. The nozzle can advantageously be a variable converging-diverging nozzle (e.g., CD nozzle, de Lavel nozzle), which can be configured as described herein.

The HAT system can be configured with the catalystless nitrous decomposition system in order to supply clean simulated air at high Mach numbers (e.g., high speed, up to Mach 8) with flight enthalpies for a length of time to simulate a mission duration for a test object (e.g., wing, plane, spacecraft, missile, etc.). The catalystless nitrous decomposition can provide the clean simulated air from the nitrous dioxide (e.g., N₂O, or “nitrous”) breaking down into the two largest elements of atmospheric air, which are gaseous nitrogen and oxygen. As such, the working fluid in the HAT system can simulate clean air so that the testing can provide enhanced data that is free from the impacts of contaminates, particles, or other problems that may occur by other systems. Since the catalystless nitrous decomposition yields larger percentages of oxygen over nitrogen than is found in “air” (e.g., reference U.S. 1976 Standard Atmosphere), nitrogen gas can be introduced into either the nitrous prior to or at the time of decomposition or to the decomposition product fluid in order to obtain simulated air with the desired amounts of nitrogen and oxygen, such as about 80% nitrogen and 20% oxygen (79% nitrogen and 21% oxygen). However, the relative amount can be tailored as needed or desired by modulating the amount of nitrogen gas introduction. Because of the exothermic reaction of catalystless nitrous decomposition, the product fluid (e.g., also used as the process fluid, test fluid or working fluid of a wind tunnel) has a high temperature and velocity. This product fluid is then provided to the variable CD nozzle so that the increase in velocity at the nozzle throat can match the enthalpy of real air with a given Mach number. That is, the variable CD nozzle can be used to modulate the air flow to obtain the desired air parameters, such as temperature and velocity. This provides the HAT with the ability to provide the working fluid at various conditions to test an object in a hypersonic tunnel test laboratory setting. This approach can provide virtually unlimited simulated “air” at correct enthalpies with the temperature and velocity expected in a real environment for a specific type of test object at a test altitude, which is an improvement over other approaches. The HAT can provide and implement three advancements for enhancing existing test capabilities. Those advancements have the ability to: supply clean air at HM/HS flight enthalpies with real-time changes to Mach number corresponding to mission scenarios (e.g., expected experienced temperature); vary Mach numbers and altitudes within a single test system at appropriate scales (e.g., expected transition in changes); and execute test processes over real mission length durations (e.g., expected time each Mach number is experienced).

FIG. 1 shows a wind tunnel system 100 that produces a working fluid from catalystless nitrous decomposition. The wind tunnel system includes a gas supply 102 fluidly coupled with the inlet opening of the nozzle 10 that is in a test cell 104 having at least a portion of the nozzle 10 therein. The test cell 104 is coupled to an exhaust outlet 106 fluidly coupled with the outlet opening of the nozzle 10 with a test region 109 within the test cell 104 between the outlet opening of the nozzle 10 and exhaust diffuser 106. The gas supply 102 can include a gas generation system 108. The gas generation system 108 is configured for decomposing nitrous oxide without a catalyst to generate heat and obtain a Mach number of gas flow in the nozzle 10.

FIG. 1 shows the gas supply 102 includes primary and secondary reservoirs of nitrous (N₂O) supply tanks 110 operably coupled to a gas supply control valve 112 that controls inlet into the decomposition chamber 114 of the gas generation system 108. One of the tanks 110 can optionally be nitrogen. One of the tanks 100 can be any other gas or element for use in the process, such as those described herein. The nitrous can be decomposed as described herein and as in the incorporated provisional application and other incorporated references. The nitrous is added and heated in the decomposition chamber 114 for decomposition into a decomposition gas, which is nitrogen and oxygen. The decomposition gas is passed through the rupture disks 116 and then the mixing/stilling chamber 118 before passing through the flow valve 120 into the forward adapter 122. The forward adapter 122 includes the inlet of the CD nozzle 10 which extends into the test cell 104. The test cell 104 is fluidly coupled with the forward adapter 122, and contains the CD nozzle 10 and the test article 130 downstream from the CD nozzle outlet. The test article 130 is shown between the CD nozzle 10 and the exhaust diffuser 132. The exhaust diffuser 132 is in the test cell 104, with the outlet thereof being coupled to the inlet to the ejector diffuser 134, which can include the exhaust 106.

A gas injector system 150 is included that has air injectors 152 (e.g., annular or center body) configured to inject gas (e.g., air or mixture simulating air) around the ejector diffuser 134. The air injectors 152 inject air from high pressure air tanks 154 coupled via control valves 156 (e.g., controlled by the controller 175), which provide the pressurized air into the ejector diffuser 134, which is within the exhaust duct 106.

The gas supply 102 can provide the nitrous or from a source of nitrous. The nitrous source can comprise nitrous oxide and can be configured to introduce the nitrous oxide as a liquid and/or a gaseous composition into the chamber. The nitrous oxide can be in a liquid state, a gaseous state, or combinations thereof. The nitrous oxide can be at least 90 percent pure by volume, such as, for example, at least 95 percent pure by volume, at least 99 percent pure by volume, at least 99.9 percent pure by volume, or at least 99.99 percent pure by volume. In various examples, the nitrous oxide source can comprise a component other than nitrous oxide. For example, the nitrous oxide source can be a nitrogen oxide source. For example, the nitrogen oxide source can comprise NO, nitrous oxide (N₂O), NO₂, N2O₃, N₄O, N₂O₃, N₂O₅, N₄O₆, or combinations thereof. In various examples, the nitrous can be a blend with an additional component such as for example hydrogen (e.g., to reduce the oxygen content in non-vitiated air and/or generate water vapor). The composition of the nitrogen oxide and/or blend can be configured such that non-vitiated air is generated by the system with a desired composition and at desired test conditions. The nitrous can be at room temperature (e.g., 20 degrees Celsius), cooled to a temperature lower than room temperature, or heated to a temperature higher than room temperature. The nitrous can be introduced into the chamber 114 at an inlet pressure in a range of 100 psig to 10,000 psig, such as, for example, 500 psig to 3,000 psig or 750 psig to 3,000 psig. The chamber 114 can be configured to convert the nitrous from the nitrous source into non-vitiated air at the desired test conditions. The conversion of the nitrous into non-vitiated air can comprise a catalystless thermal decomposition, and thereby can be devoid of a catalytic decomposition, a shock decomposition, a combustion decomposition, or combinations thereof. For example, the nitrous from the nitrous source can undergo a catalystless thermal decomposition event in the chamber 114.

In some embodiments, the nitrous decomposition product is considered to be a test gas or working fluid that is provided to the variable nozzle flow path. The nitrous decomposition product can be non-vitiated air. The phrase “non-vitiated air” as used herein refers to a gas composition that is substantially free of contaminates (e.g., carbon-based particulate) and comprises a composition substantially similar to atmospheric air. In general, it has been found that vitiation contamination has a profound effect on vibrational relaxation, combustion kinetics, condensation and overall test engine performance. The non-vitiated air can be substantially similar to atmospheric air. The phrase “substantially similar to atmospheric air” means the non-vitiated air composition can comprise 10 percent to 45 percent oxygen gas, 55 percent to 90 percent nitrogen gas, and 0 percent to 5 percent of other components, such as, for example, argon, carbon dioxide, neon, helium, and water vapor, all on a volume basis. For example, the non-vitiated air composition can comprise 15 percent to 35 percent oxygen gas, 65 percent to 85 percent nitrogen gas, and 0 percent to 5 percent of other components, all on a volume basis. In various examples, a non-vitiated air composition can comprise 18 percent to 24 percent oxygen gas and 76 percent to 82 percent nitrogen gas, all on a volume basis. For example, the non-vitiated air can comprise 21 percent oxygen gas, 78 percent nitrogen gas, and 1 percent of other components, all on a volume basis. The non-vitiated air composition can comprise diatomic and homonuclear oxygen gas and nitrogen gas. Non-vitiated air may not be vitiated air. The non-vitiated air generated by the chamber can comprise desired test conditions, such as, for example, a desired test speed, a desired test composition, a desired test pressure, and a desired test temperature. The desired test speed can be in a range of Mach 1 to Mach 20, such as, for example, Mach 2 to Mach 10, Mach 3 to Mach 7, or Mach 5 to Mach 10. As used herein, the term “Mach” refers to the velocity of an object relative to the speed of sound (e.g., Mach 1=one times the speed of sounds, Mach 2=two times the speed of sound). The desired test pressure can be in a range of 0.1 psia to 50 psia, such as, for example, 1 psia to 30 psia or 1 psia to 14.6 psia. The desired test temperature can be in a range of 1,000 degrees Fahrenheit to 4,000 degrees Fahrenheit, such as, for example, 2,000 degrees Fahrenheit to 4,000 degrees Fahrenheit or 2,500 degrees Fahrenheit to 4,000 degrees Fahrenheit.

The test chamber having the nozzle and test area can be configured to receive a device to be tested and subject the device to non-vitiated air from the system for generation of non-vitiated air at the desired test conditions. The device can be a HS/H device, such as, for example, an aerospace vehicle or component. For example, the device can be a ram jet, a scram jet, a ducted rocket, a thermal protection system material, a HS/H jet, a drone, a weapons system, an engine, an engine component (e.g., a compressor blade, an isolator, a combustor), a heat exchanger, or combinations thereof.

FIG. 2 illustrates an example of a nitrous decomposition system 200, which can be used in the a wind tunnel system 100, such as by being the gas supply 102 and gas generation system 108. As shown, the system 200 includes a nitrous supply 202 having a tank 204 with a pressurized bladder 206 separating pressurized nitrogen 208 from pressurized nitrous 210 (e.g., liquid). The tank 204 can be a fully instrumented, heated, metal tank (e.g., aluminum, stainless steel, etc.) connected to pumps and/or compressors to provide pressure to the pressurized nitrogen in one compartment that presses the pressure bladder 206 to have pressurized nitrous 210 in another compartment. Within the tank 204, the nitrous 210 has a temperature T1 and a pressure P1. A conduit 201 is connected (e.g., through valves, pumps, etc.) to the nitrous 210 to obtain a flow thereof with a second temperature T2 and pressure P2 profile that passes through a heating system 214, which can provide a pre-phase change temperature, such as with a ceramic heater 216 or heat exchanger or other heater, to obtain a third temperature T3 and pressure P3 profile. A metering valve 218 controls nitrous flow into another heating system 220 that is configured to further heat the already preheated nitrous to a temperature for decomposition of only the nitrous, such as with a ceramic heater 222 or heat exchanger or other heater. As the preheated nitrous passes through the metering valve 218, a fourth temperature T4 and pressure P4 profile are obtained. Then the heating system 220 provides a fifth temperature T5 and pressure P5 profile prior to entering the decomposition reactor 230.

The decomposition reactor 230 receives the heated nitrous in a nitrous inlet 232 for decomposition into nitrogen and oxygen. However, the nitrogen content is lower than in normal air. Accordingly, the decomposition reactor 230 is fluidly coupled to a heated nitrogen system 240 that includes a nitrogen source 242 with a nitrogen heater 244 that provides heated nitrogen into a nitrogen inlet 234, which passes the heated nitrogen through a nozzle 236 into the reactor chamber 238. The reactor chamber 238 is configured for nitrous decomposition from heat of the heated nitrous and heated nitrogen, which is configured to provide for thrust (e.g., thruster chamber). The reactor chamber 238 is pressurized from at least the nitrogen and nitrous introduced therein as well as the increase in molecules from the dissociation of nitrous into nitrogen and oxygen. The high temperature injection of heated nitrogen gas can facilitate the decomposition of the heated nitrous. While heated nitrous may auto dissociate, the addition of heated nitrogen facilitates the decomposition. The amount of nitrogen added can result in 80/20 (79/21) nitrogen/oxygen air. The generated non-vitiated air can then be provided to the nozzle for acceleration before contacting the test object. While only two heated nitrogen systems 240 are shown, any number can be used. Additionally, other gases, such as hydrogen, oxygen, or other can be introduced into the system at various locations, such as with the heated nitrous or heated nitrogen before the decomposition reactor 230, or within the decomposition reactor 230, or downstream therefrom. The other gases can be provided by gas systems 250 that provide gas, whether heated or unheated. The system can provide non-vitiated air that simulate the atmosphere where a test object will be operating, which can provide for the temperature and pressures that are likely to be experienced in real live flight.

The system can be used to test aerodynamics for the test object as well as for the mechanical operations thereof, such as for airbreathing devices that utilize air for operation. The system can provide the air at the operational temperature, pressure, and velocity experienced during flights at any altitude. The other gases can be provided to allow for tailoring the output working fluid. For example, pollution components can be included to mimic operation in polluted environment. However, pristine non-vitiated air can be achieved by only using the nitrogen, nitrous, and optionally hydrogen and oxygen.

For example, the system can produce an air that ranges from low speed Mach 3 simulating 35,000 feet at a temperature of 1193 degrees Rankine and pressure of 129 psai with a flow of 50.3 lbm/s; to low speed glide Mach 5 simulating 70,000 fee at a temperature of 2211 degrees Rankine and pressure of 384 psai with a flow of 15.7 lbm/s; and to high speed Mach 8 simulating 115,000 feet at temperature of 4889 degrees Rankine and pressure of 1349 psai with a flow of 3.06 lbm/s. The system can run for greater than 16 minutes and vary the conditions of the working fluid through the ranges by modulating the input flow and varying the variable CD nozzle (e.g., throat area).

FIG. 3A illustrates a decomposition nozzle 300 having an outer tube 302 with an inner tube 304 concentrically contained therein. The outer tube 302 can contain the heated nitrogen and the inner tube 304 can contain the heated nitrous, or vice versa. FIG. 3B shows the spray decomposition in the reaction chamber, which provides for swirling fluid flow with recirculation. A corner recirculation zone 306 is shown along with the traditional centerline gas turbulent zone 308, with heated nitrogen outside of the heated nitrous. As shown, the dashed line in FIG. 3A corresponds with the placement of the dashed line in FIG. 3B for comparison purposes. The liquid nitrous can be under at least 750 lbs of pressure so that it is released and expands into the outer tube with the heated nitrogen, which can cause the decomposition. The isotropic expansion of the nitrous makes it cool down, where the heated nitrogen inhibits this cooling. The heated nitrogen can induce the nitrous to decompose after it expands.

FIG. 3C illustrates an example of decomposition nozzle 300 that further includes turning vanes 310 positioned throughout the outer tube 302. The turning vanes 310 can be configured for turning the nitrogen into the nitrous, and vice versa. The turning vanes 310 are illustrated as rectangles; however, they can be in any configuration (e.g., arced, turned, curved, bowed, cornered, etc.) that turns the flow direction, such as in an efficient turning with a low branch loss coefficient. Any number of turning vanes 310 can be used in any placement in any spacing distance therebetween. Also, the inner tube 304 can be perforated or include aperture or holes along a length thereof to increase mixing of the heated nitrogen and the cooled nitrous (e.g., cooled from isotropic expansion). The configuration uses an expansion of a corner region to provide a larger recirculation zone with enhanced mixing.

FIG. 3D shows the turning vanes 310 a have a curved shape that curve back towards the flow direction to enhance turbulence and mixing between the nitrogen and nitrous.

FIG. 3E show a staggered placement of turning vanes 310 b to form a tortuous pathway which results in mixing of the nitrogen and nitrous.

The use of turning vanes or other feature to enhance the mixing of the nitrogen and nitrous can enhance the decomposition. The thermally heated nitrogen is swirl stabilized with sprayed liquid nitrous to obtain thermal decomposition into nitrogen and oxygen. Additionally, a fully dissociated nitrous field appears to be uniform with stabilizing from correct oxygen and nitrogen levels to simulate air. The turning vanes may be replaced or combined with any type of structure that causes turbulence or swirling of the nitrogen and nitrous or otherwise enhances the decomposition. The turning vanes may also be replaced or combined with perforated flow paths, helical flow paths, annular members, angled members, arced members, or other features or combinations thereof in accordance with the teaching of causing turbulence, mixing, and nitrous decomposition.

FIG. 4A shows the oxygen (O₂) mass fraction stabilizing after about 0.9 seconds of dissociation. FIG. 4B shows the temperature in Kelvin with the nitrogen being heated to above 1600 degrees K, and the liquid nitrous isotropically expanding into the turning vane 310 and quickly increasing temperature to 1600 degrees K from mixing with the heated nitrogen.

FIG. 4C shows the oxygen mass fraction over time for different pressures, where the higher pressures above 250 psi, especially above 350 psi, and especially above 384 psi appear to enhance nitrous decomposition. FIG. 4D shows the temperature profile obtained for the different pressures. The data indicates that the different pressures can provide different atomization of the swirling of the nitrogen and nitrous mixture and decomposition products thereof and better mixing of the fluid. This provides a more uniform working fluid for testing on the test object.

FIG. 4E shows the oxygen mass fraction over time for different temperatures, where the higher temperatures above 1300 degrees K, especially above 1400 degrees K, especially above 1500 degrees K, and especially above 1600 degrees K appear to enhance nitrous decomposition. FIG. 4F shows the temperature profile obtained for the different temperatures. However, nitrous can begin decomposition at about 900-950 degrees K, which may be useful lower limit in some operational parameters. However, boosting the temperature of the nitrogen up to 1300 degrees K significantly enhances the decomposition and overall thermal decomposition product profile.

In some embodiments, the nitrous and nitrogen are each independently heated by any heating method, such as arc, ceramic, heat exchanger (e.g., with hot gas from a burner, such as propane), or other that can generate the desired temperature. The heating is prior to introduction into the decomposition chamber.

As shown herein, FIGS. 3C-3E provide schematic illustrations of the mixing members, which are configured as turning vanes, barriers, baffles, or other flow direction changing or mixing device. FIGS. 4B, 4D, and 4F show the profiles when the mixing member (turning vane) is used to mix the heated nitrous with the heated nitrogen.

These figures show a one dimensional cross section of an example for swirl stabilization, where the focus is to increase resonance time of the two mixed gasses (e.g., “cold” nitrous dioxide sprayed and swirled with “hot” nitrogen). The nitrous dissociation initiation and stabilization process within the reaction chamber can occur in three distinct phases. Phase I is the formation of a kernel of nitrous dissociation of sufficient size and temperature to be capable of propagation. Phase II is the subsequent propagation of this dissociation process from this kernel to all parts of a single instigated nitrous dissociation injection process. Phase III is the spread of the nitrous dissociation process from one instigated nitrous dissociation injection system process to adjacent undissociated nitrous regions within the reaction chamber. A failure of any of the above steps may result in a failure to stabilize the entire nitrous dissociation process. Recognition of the multi-phase nature of the nitrous dissociation process helps to focus on various dissociation system anomalies potentially present within a thermally driven nitrous dissociation process.

Phase I includes the kernel formation. The survival of a kernel of dissociated nitrous to be created by gasses emanating from a source of heated nitrogen, depends on whether or not the rate of heat release by the heated nitrogen exceeds the rate of heat loss to the surroundings by radiation and/or turbulent diffusion. This rate of ignition and/or heat release can be governed mainly by the effective enthalpy addition injected into the local nitrous/nitrogen injection process. Kernel size and temperature will be determined by the energy and duration of the anticipated torch system.

Phase II includes nitrous dissociation propagation. The success or failure of this phase is governed largely by the location of the dissociation initiation source (e.g., heated nitrogen) relative to the nitrous/nitrogen mixing. This process determines whether the hot kernel is entrained into a local nitrous/nitrogen flow reversal regime or is swept away downstream. The nitrous/nitrogen injection process within the reaction chamber can be composed of multiple individual swirl stabilized injection assemblies. Nitrous injection can be accomplished with one or more discrete orifices depending upon the state (e.g., gas or liquid) of the nitrous when in the reaction zone. These orifices can be in simplex injector form as nitrous is injected as a liquid or in a multiple orifice arrangement as gaseous nitrous is injected. The swirl can be a measure of the angular velocity of the decomposition gasses, which is characterized by the swirl number, S, defined as the ratio of the axial flux of angular momentum to the axial flux of linear momentum (Gupta et al., 1984). The degree of swirl imparted on the nitrous can range from zero to a swirl number exceeding 0.40 (forty).

$S = {\frac{\sigma\; R}{2B}\left\lbrack {1 - \left( {R_{h}/R} \right)^{2}} \right\rbrack}$ $\sigma = \frac{\tan(\alpha)}{\left( {1 - \Psi} \right)\left\lbrack {1 + {{\tan(\alpha)}{\tan\left( {\pi/z} \right)}}} \right\rbrack}$ $\Psi = \frac{zt}{2\pi\; R_{1}{\cos(\alpha)}}$

wherein, Z is number of turning vanes, t is vane thickness, B is vane height, R1 is distance from axis to vane, R is outer diameter of exit duct, Rh is inner diameter of exit duct, and S is the swirl number.

The geometry and nitrous dissociation operation of one of these injection arrangements is schematically summarized in FIG. 7A, which shows the pre-heated nitrogen supply into the reactor along with the nitrous injection (e.g., liquid or gas). FIG. 7A shows a schematic depiction of swirl stabilized nitrous dissociation that utilizes liquid or gaseous nitrous injection encapsulated by pre-heated and swirled nitrogen.

There is a potential for a nitrous/nitrogen injector to “blow out” at any point during operation. Therefore, there is a need for each injection process to be communicating with adjacent injection processes throughout the operation of the reaction chamber. This process could be limited within the injection system schematic shown in FIG. 7A. The configuration of the nitrous/nitrogen injection process can be such that it features a very strong swirl component, such as from the mixing member (e.g., turning vanes, baffles, etc.). This can be done by incorporating a swirling device, such as a large circumferential component with turning vanes, into the pre-heated nitrogen injection process as depicted in FIGS. 7B-7C. FIG. 7B includes a graph showing the use of the swirled nitrogen circumferential component (e.g., swirler 700) within each injection assembly improves nitrous/nitrogen dissociation stability via recirculation and injector-to-injector communication via greater flame spreading. FIG. 7C includes an image of a simulation to demonstrate the potential of high swirl number nitrogen injection to improve stability and communication with the swirler 700. The circumferential nitrogen exit velocity component is within the reaction chamber nitrous/nitrogen injector and configured to provide additional dissociation stability and injector-to-injector communication.

One of the advantages of the nitrous/nitrogen swirled injection approach (e.g., swirled mixing) is that a swirl induces nitrous dissociated products to flow upstream to meet and merge with incoming undissociated nitrous and unmixed nitrogen. For weak swirl there is little or no flow recirculation, but when the swirl number is increased and reaches a critical value greater than 0.4 the static pressure in the central core just downstream of the swirl becomes low enough to create flow recirculation as indicated in FIG. 7B. This process can be used for stabilizing the dissociation process and reducing peak-to-peak pressure oscillations within the reaction chamber that are independent of the nitrous dissociation instigation process and subsequently minimized due to feed system irregularities.

FIG. 8 includes images of testing that shows a current nitrous oxide/nitrogen atomizer and vaporization device, where “cold” nitrous oxide is injected as droplets via a droplet generation device (e.g., Schlick model 556 simplex atomizer) with the intent to vaporize the nitrous oxide into a nitrogen slip steam (i.e., annular surrounding) nitrogen gas. The photographs, obtained from testing which used water as a substitute for the nitrous oxide for illustration purposes, is intended to show a non-swirl scenario. Various flow rates of water and nitrogen are shown in FIG. 8.

FIG. 9A shows an embodiment of a decomposition reactor 230 that receives the heated nitrous in a nitrous inlet 232 for decomposition into nitrogen and oxygen. The decomposition reactor 230 is fluidly coupled to a heated nitrogen system that includes a nitrogen source with a nitrogen heater that provides heated nitrogen into a nitrogen inlet 234, which passes the heated nitrogen through swirler 700 into the reaction chamber 238. The reactor chamber 238 is configured for nitrous decomposition from heat of the heated nitrogen, which is configured to provide for thrust from the outlet 239 of the decomposition reactor 230. As shown, the swirler 700 is configured with a plurality of swirling members 702 about the swirling conduit 704. The swirling members 702 cause the nitrogen to be swirled as it enters the reaction chamber 238 with the nitrous, such that the nitrogen and nitrous are swirled together to enhance mixing and thereby enhance nitrous decomposition. However, it should be recognized that the nitrogen inlet and nitrous inlets can be swapped, such that the nitrous is sprayed through the swirler.

FIG. 9B shows the swirler nozzle system 710, which includes the swirler 700 having the central orifice 712 and swirling concentric orifice 714. FIG. 9C shows the swirler 700 without the lumen walls of the swirling conduit 704. As such, the swirling members 702 are shown to be spaced apart circumferentially around the central orifice 712. The swirling members 702 are shown to have an arced shape to cause a change in the fluid flow into the reaction chamber 238. The swirler 700 can be part of the pipe forming the nitrous inlet, or it can be coupled thereto or fit therearound. FIG. 9D shows the swirler nozzle 720 having the central conduit 722 and swirling concentric conduit 724, with orifices defined by the space between each swirling member 702.

FIGS. 10A-10D show a swirl nozzle 800 that is adapted to be inserted into the central orifice 712 of the swirler 700, or otherwise be located in the central conduit 722 so as to provide for a swirling spray therefrom into the reaction chamber 238. That is, instead of an open nozzle, the swirl nozzle 800 can be used so that both the central orifice 712 and swirling concentric orifice 714 provide swirling. Mixing can be enhanced when both the nitrous and nitrogen are swirled when sprayed into the reaction chamber 238.

FIG. 10A shows the swirler 700 having the swirl nozzle 800 in the central orifice 712, where the swirl nozzle 800 is shown with four swirl nozzle openings 802. FIG. 10B shows the swirl nozzle inlet side 804, which shows the swirl nozzle conduits 806 somewhat near the center axis. FIG. 10C shows the swirl nozzle outlet side 808 that sprays from the four swirl nozzle openings 802 into the reaction chamber, however, any number of swirl nozzle openings can be used for swirling. As shown, the trajectory of each swirl nozzle opening 802 is adapted to cause the spray to swirl, as they are all pointed outward and radially away from each other. FIG. 10D shows the swirl nozzle conduits 806 extending from the middle on the inlet side 804 outwardly to the swirl nozzle openings 802 on the outlet side 808.

The FIG. 2 can be considered to be a schematic of the basic layout for a swirl stabilized, nitrous oxide via heated nitrogen, decomposition system. In the swirl injection for decomposition schematic (above), the nitrogen thermal conditioning feed subsystem (e.g., 240) is responsible for controlling and conditioning nitrogen gas flow at the correct pressure and temperature to feed into the swirler decomposition section of the decomposition chamber 238. The flow from the nitrous oxide feed subsystem (e.g., 202) takes liquid nitrous oxide and conditions it to the desired temperature and pressure to feed it, as a liquid, into the swirl decomposition section of the decomposition chamber 238 with the heated nitrogen. The nitrous can remain a liquid until it enters the swirl decomposition section in order to avoid spontaneous decomposition, whereas the nitrogen is a gas when injected into the swirl decomposition section. The heated nitrogen gas, acting on the liquid nitrous dioxide, will both flash, swirl, and decompose the nitrous dioxide.

In some embodiments, the present invention includes the use of heated nitrogen to raise the temperature of nitrous (e.g., liquid, preferably heated) that has been expended into a gas and cooled. The nitrogen is heated as described herein and is mixed with the nitrous as it is sprayed into a decomposition chamber. The heated nitrogen thereby raising the temperature of the gas nitrous to allow for decomposition.

In some embodiments, the decomposition of nitrous can be performed without a conversion accelerator that is disposed in the decomposition chamber to accelerate conversion of nitrous oxide. Instead of a conversion accelerator deposed in the decomposition chamber, the present invention uses the heated nitrogen that is sprayed into the decomposition chamber along with the sprayed nitrous to produce the process gas. The process gas in this application arises from conversion of nitrous (e.g., decomposition) into nitrogen and oxygen gas to simulate air. This decomposition occurs in the decomposition chamber from heated nitrogen introduced directly into the chamber. That is, the nitrogen is heated prior to entering the decomposition chamber. While the nitrous may be heated, there may be cooling of the nitrous due to expansion into the gas within the decomposition chamber, which can cause temperature loss. In some aspects, the present invention omits the use of any conversion accelerator in the decomposition chamber, such as omitting a heater, a catalyst, a shock tube, or combustion chamber in the decomposition chamber. The conversion accelerators are not considered to be heated nitrogen, that is preheated prior to injection into the decomposition chamber.

In some embodiments, the process can be performed by also introducing a secondary gas, such as a gas other nitrogen into the chamber via a port. The secondary gas can also be heated prior to mixing with the nitrous or process gas produced therefrom. The process gas is not nitrous, but instead is nitrous degradation products. The secondary gas can be mixed with the nitrous or with the degradation produces. However, the present invention can specifically omit introduction of any secondary gas into the heated nitrogen or nitrous prior to formation of the process gas. Instead, the secondary gas can be injected into the process gas, such as by the location of a port being downstream from a reaction zone. The secondary gas can be introduced so that it mixes only with the process gas obtained by the nitrous decomposition.

In some embodiments, the process includes preheating nitrogen to a nitrous decomposition temperature, and injecting the preheated nitrogen into a chamber with nitrous to heat the nitrous to the nitrous decomposition temperature. Thereby, the nitrous decomposes. The decomposition can be obtained without any additional conversion accelerators, which are not heated nitrogen. The decomposition can be enhanced by “mixing” or otherwise swirling the nitrogen and nitrous together in the decomposition chamber. The swirling can result from the turning vanes or other features that cause turbulence in the sprays into the decomposition chamber. The amount of the heated nitrogen can induce nitrous decomposition into “air”. Thus, the preheating of nitrogen to a nitrous decomposition temperature, and injecting the preheated nitrogen into a decomposition chamber with nitrous to heat the nitrous to the nitrous decomposition temperature can be used to obtain “air”. The “air” can then be directed to a variable CD nozzle in a wind tunnel setting.

FIG. 5 illustrates one embodiment of a wind tunnel 500 comprising a variable dimension three-dimensional (3D) throat 502. As shown, the wind tunnel 500 includes a variable three-dimensional throat 502, an entry section 532 coupled to a first side of the three-dimensional throat 502, and an exit section 534 coupled to a second side of the variable three-dimensional throat 502. The entry section 532, the three-dimensional throat 502, and the exit section 534 define a flow path. The three-dimensional throat 502 comprises the body 504 formed of the interconnected plurality of elongate members. The body 504 comprises a form that is flexible so that the dimensions can be adjusted. An air source, as described herein, is configured to provide air flow from the entry section 532 to the exit section 534. The three-dimensional throat 502 provides a variable cross-section 506 that can have the area thereof expanded or contracted, in symmetrical 3D shape around the center axis (axisymmetric). The three-dimensional throat 502 maintains a well-conditioned air flow while varying the flight Mach number within the wind tunnel 500 continuously within a predetermined range, such as, for example, Mach 1-8. The operational Mach range of the wind tunnel 500 is related to the area ratio change of the three-dimensional throat 502. For example, in one embodiment, an area ratio change factor of 12 may allow continuous operation within a range of Mach 3-6. As another example, in one embodiment, an area ratio change factor of 50 enables continuous operation over a range of Mach 3-8.5

The three-dimensional throat 502 is variable in area to produce a variable cross-section 506 between the entry section 532 and exit section 534. The three-dimensional throat 502 provides a continuously changeable air speed within the predetermined range. For example, in one embodiment, a three-dimensional throat 502 provides a continuously variable air speed within the range of Mach 1, 2, or 3 to Mach 8 or even higher. In one embodiment, the three-dimensional throat 502 is coupled to one or more actuators 524 configured to continuously vary or set the cross-section 506 of the three-dimensional throat 502 from a first cross-section to at least a second cross-section.

The gas temperature and pressure in the three-dimensional throat 502 increases with increasing Mach numbers. In some embodiments, the flexible body 504 is configured to allow uncooled operation of the wind tunnel 500 up to a predetermined Mach speed having a corresponding temperature. For example, in one embodiment, the body 504 comprises a Nomax fiber weave capable of continued operation at temperatures up to 2300° F. corresponding to Mach numbers up to about Mach 8. For higher Mach numbers, and corresponding higher temperatures, an active cooling system is coupled to the three-dimensional throat 502, such as by cooling with a barrier gas passed through the apertures between the members that form the flexible body 504. For example, in one embodiment, the body 504 includes one or more holes and/or apertures and/or ducts between the members for coupling to an active cooling system, such as cooling barrier gas. Active cooling systems may comprise, for example, back-face cooling utilizing a cavity filled with a flowing or static gas, a coolant fluid passed through one or more cooling channels attached to and/or formed in the body 504, and/or transpiration using holes and/or ducts (e.g., aperture) formed in the body 504. Cooling systems may be selected, for example, based on the heat flux that can be tolerated by the cooling system.

The CD nozzle body 504 is shown to be within the fluid-tight housing 550 having an internal chamber 551 that contains the flexible body 504. The fluid-tight housing 550 includes at least one gas inlet valve 552 in the housing 550 to provide pressurized barrier gas to the internal chamber 551. Also, a pump 554 can be operably coupled to each gas inlet valve 552 to provide a barrier gas supply 556 as the pressurized barrier gas to the internal chamber 551.

The adjustable CD nozzle body 504 is shown to include at least one means 522 for changing a shape of the flexible body 504 to change a dimension or location of the throat plane relative to at least one of the inlet plane or outlet plain. Also included is at least one articulatable member 524 that can articulate the body 504 to change the shape of the adjustable CD nozzle body 504. The figure also shows the anchors 539 that couple the articulatable member 524 with the body 504 or individual elongate nozzle body members.

FIG. 5 also shows the anchors 539 that couple the articulatable member 524 with the body or individual elongate nozzle body members (e.g., of weave).

Also, the CD nozzle 500 can include at least one means for changing the shape of the flexible nozzle body 504 that includes at least one circumferential assembly 522 that has at least one articulatable member 524 that defines an aperture 506 having an aperture plane 508 with a variable area when articulated.

The inlet test gas has an initial gas pressure P_(o), initial gas density ρ_(o), and initial temperature T_(o) with a velocity of V, with the cross-section are being S_(x) (as a function of distance from the inlet to the position x), which are then used to determine the outlet pressure p, density ρ, and temperature T.

In some embodiments, the wind tunnel can receive the generated working fluid from a variable (e.g., adjustable on the fly) converging-diverging (CD) nozzle that can have the nozzle throat plane varied in area or location under mechanical control. The result is a variable, three dimensional (3D) CD nozzle that can have a variable mass flow and a Mach number that is capable of being varied during operation. That is, the nozzle throat plane can be varied by automated mechanisms that change the area of the throat plane and/or location of the throat plane relative to an inlet and/or outlet opening of the CD nozzle. The changes can be axisymmetric for the nozzle central axis. The CD nozzle is outfitted with a mechanical system that is configured to manipulate the flexible body of the nozzle in order to manipulate the shape of the flow path in the nozzle in an axisymmetric manner.

In some embodiments, the body of the variable CD nozzle includes the plurality of flexible members that are interlocked together, such as in a braid or weave, or the like. The flexible members can be in various forms, such as those described herein, which can include elongate bodies of temperature resistant materials that are associated together. The body can include some flexible members in a clock wise rotation from inlet to outlet interlocked with some flexible members in a counter-clock rotation. The differently oriented flexible members can also be axial members and radial members that are interconnected together.

In some embodiments, the CD nozzle is configured as a variable dimensional venturi for varying and setting Mach numbers in a wind tunnel. The body of the CD nozzle can be formed from the plurality of interconnected elongate members of a ceramic and/or composite and/or metallic material that can withstand high temperatures of Mach wind tunnels. The body can resemble a “cloth” configured with interconnected members (e.g., strands, ribbons, etc.). The body can be configured similar to a finger trap, and can be manipulated similarly. The nozzle can include a plurality of flexible members interconnected together. The flexible members can be clockwise members (axial) and counterclockwise members (radial) that are interlocked together so that there are apertures therebetween (e.g., at junction of the clockwise members and counterclockwise members), such as slit apertures between adjacent surfaces. The members can be configured as sliding ribbons or cords, wherein the dimensions of the nozzle change depending on the forces applied thereto or to the body overall. The nozzle is an example of an axisymmetric design, where the 3D volume around the central axis is uniform or symmetrical.

The plurality of flexible members are movably interconnected together by a movable interlace, interweave, intertwine, plait, entwine, cross-cross, weave, knit, lace twist, wind or other association thereof to form the flexible body. The individual flexible members can include cord, thread, string, strap, tape, line, rope, cable, wire, ligature, twine, yarn, ribbon, strip, fiber, filament, petal, sheet, or combinations thereof or interlace, interweave, intertwine, plait, entwine, cross-cross, weave, knit, lace twist, wind, needlefelt, woven fabric, wet-laid nonwoven, dry laid nonwoven, and spunlace nonwoven, thereof for each flexible member. As such, each member can be a monofilament or a multifilament configuration. The flexible body includes apertures (e.g., slit apertures) between the plurality of flexible members 16 a that are movably interconnected together.

In some embodiments, the flexible members can be prepared from temperature resistant materials, such as aramid fibers or fabrics, para-aramid fibers (Kevlar, Twaron, Technora, meta-aramid fibers (Nomex, TeijinConex), polytetrafluoroethylene fibers (e.g., Teflon, Toyoflon), polyphenylene sulfide fibers (Ryton, Procon, TorayPPS), melamine fibers (Basofil), poly-phenylene-benzobisoxazole (Zylon), polybenzimidazole (PBI), polyimide (P-84), pyrolytic carbonization of modified acrylic fiber (Lastan), carbon fibers (polyacrylonitrile, pitch), high density polyethylene (HDPE; Spectra, Dyneema), steel, stainless steel, titanium, tungsten, molybdenum, nickel, tantalum iron, metal alloys thereof, and combinations thereof.

FIG. 5 shows the controller 275 can be operably coupled with the actuators that are used for the means for changing the shape of the flexible nozzle body. The controller 275 and components can be operably coupled by wire, optical, wireless, etc. The controller 275 can control actuation of the actuators so that the components are moved to change the shape of the nozzle body. The controller 275 can receive input, from a user or program, to control the position and aperture area of each circumferential assembly. There can be any number of circumferential assemblies along the body 16, such as the inlet circumferential assembly, the throat circumferential assembly, or outlet circumferential assembly. Each circumferential assembly can include a at least one articulatable member that is articulated to open or close the region of the body within the aperture thereof. The controller 275 can control the position and/or aperture size of each circumferential assembly to modulate the shape of the CD nozzle as described herein. The controller 275 can be a computing device 600, such as shown in FIG. 6. The controllers 175, 275 can be the same or different computing systems, if different they can be in operable communication with each other.

The CD nozzle can be configured as a variable geometry, axisymmetric, three-dimensional structure. The structure can include a flexible series of interwoven elongate members (e.g., plates, ribbons, petals, etc.). The flexible members can be metal and/or flexible ceramic and/or flexible composite matrix sheets. The sheets can have a plurality of anchors integrally formed therein, which can be coupled to the actuators system. The flexible nozzle body configuration provides the ability to axially and tangentially apply forces and/or torque to change the hourglass shape of a variable flow venturi. The anchors can extend through a thickness of the interwoven plates for the nozzle body to be secured to the mechanical system. The nozzle body can be constructed with a hyperboloid structure using an array of thin elongate members at angles crossing each other in a double helical spiral configuration matrix or other weaving, braiding or the like. The flexible nozzle body defines a three-dimensional flow path having changeable cross-sections, depending on the application of forces. The cross-section has a variable area along the length of the flow path of the flexible nozzle body. The anchors can be configured to couple to at least one actuator system or other circumferential assembly that can change the circumference to change the cross-sectional area. The actuators can be is actuatable to vary the cross-section of the flow path by changing the shape of the flexible nozzle body. The flexible nozzle body can have a hyperboloid structure where the three-dimensional flow path axisymmetric and variable between at least a first cross-sectional area and a second cross-sectional area. The first cross-sectional area can include a generally axisymmetric circular cross-section. Also, the second cross-sectional area can include a generally circular cross-section of decreasing areas, followed by a series of increasing areas (e.g., the hourglass shape). The three-dimensional flow path in the flexible nozzle body includes a narrowed throat. The flexible elongate body members can include one or more cusp features. The cusp features can define a lenticular cross-section of the body. The flexible elongate body members can include one or more curved sheets, which may also include one or more side walls. The one or more curved sheets can be positioned about the one or more sidewalls, and wherein the one or more side walls and the one or more curved sheets define the three-dimensional flow path. The CD nozzle can also include an exhaust system.

The actuator systems can be configured for provide different forces to the plurality of flexible elongate nozzle body members to change the shape of the body. In some aspects, at least one actuator is configured to apply a pulling force. In some aspects, at least one actuator is configured to apply a pushing force. In some aspects, at least one actuator is configured to apply a torque force. In some aspects, at least one actuator is configured to apply a pushing force, wherein flexible elongate nozzle body members includes a thickness of a range of values in the order of millimeters, with sufficient thickness to withstand axial and radial loads on the nozzle body.

In some embodiments, a variable speed wind tunnel can include entry section configured to couple to an air source. The wind tunnel can include an exit section comprising a testing section. The CD nozzle can include a variable three-dimensional nozzle throat coupling the entry path and the exit path. The variable three-dimensional nozzle throat is configured to provide a continuously changeable air flow speed from the entry section to the exit section. The CD nozzle body can include a structure having a plurality of anchors integrally formed therein to apply axial and torque forces. The CD nozzle body includes porosity within the hyperboloid structure preform that is formed by the spaces between the flexible elongate nozzle body members. The anchors can extend tangentially and/or axially along the thickness of the flexible elongate nozzle body members. The CD nozzle body defines a three-dimensional flow path having a cross-section, and wherein the cross-section is variable along the length of the flow path. Also, at least one actuator is coupled to the plurality of anchors, wherein the at least one actuator is actuatable to vary the cross-section of the flow path and change the shape of the CD nozzle body to thereby change the airspeed of the test gas. An outer pressurized region can contain the variable CD nozzle, and extend over the entry path, the exit path, and the variable hyperboloid structure, including the axisymmetric three-dimensional throat. The variable hyperboloid structure three-dimensional throat provides a capability of a continuously changing air flow speed from a first speed to a second speed, or being capable of being fixed at the first speed and then the second speed during operation of the wind tunnel. In some aspects, the first speed is about Mach 2 to 3 and the second speed is about Mach 8 or higher.

In some embodiments, the porosity of the flexible CD nozzle body allows for the barrier gas to be passed therethrough into the test gas flow path. The barrier gas can be introduced in an amount sufficient to provide a simulated smooth surface from the barrier gas layer. In an example, the entire nozzle exterior can be pressurized with nitrogen or other gas, which will permeate the pores in the flexible CD nozzle body at a specified rate (e.g., as a function of pressure and mesh porosity), causing a gas barrier layer to form on the interior wall of the nozzle body. The gas barrier layer can serve to create an artificial gas interface that of a gaseous boundary layer inside the nozzle approximating a smooth surface. The barrier gas can also act as a potential cooling source if hot gasses passing through the nozzle are potentially impacting the integrity of the nozzle body or the circumferential assemblies (e.g., iris mechanisms, loop mechanism, actuators, etc.).

The CD nozzle embodiments described herein can be used in methods for changing airflow in a nozzle and for testing an object with gas flow provided by the CD nozzle. The CD nozzle can be operated with the wind tunnel system described herein.

In some embodiments, a method of changing airflow in a nozzle can include providing the nozzle and operating the at least one means for changing the shape of the flexible body to change the dimension or the location of the throat plane relative to at least one of the inlet plane or outlet plane of the nozzle. The nozzle can be operated to change the shape of the nozzle as described herein, where the actions and articulations are included in the methods. The nozzle body can change shape by articulations that move the flexible members relative to each other, such as to narrow or widen the nozzle throat, or move location of the nozzle throat relative to the inlet and outlet. The inlet can also be manipulated, which is usually only having a circumferential change that modifies the inlet cross sectional area. The outlet can be manipulated to change the area of the opening or move the outlet closer or further away from the nozzle throat. The method can also include modulating the inlet gas flow in order to change the airflow. The change of the airflow and/or shape of the CD nozzle can be performed during operation, such as testing a plane design. The method can also include modulating the glow rate of the barrier gas that is introduced through the body apertures between the body parts (e.g., elongate flexible members). The thickness of the barrier gas between the test gas and an internal surface of the body flow path can be modulated by modulating the barrier gas flow rate.

A method of testing an object can include providing a wind tunnel that includes the CD nozzle with a downstream test cell. The method can include placing a test object in the test region of the test cell. Then, the method can include passing a test gas from the outlet opening of the nozzle onto the test object. The properties of the test object can then be assessed, such as with thermocouples or other temperature testing device testing temperature at various locations on the test object, such as fuselage, wings, aviators, rudders, ailerons, or the like. The airflow past the test object and any changes imparted to the airflow from the test object can be monitored and analyzed.

The methods can include steps for operating the means for changing the shape of the flexible body to change the dimension or the location of the throat plane relative to at least one of the inlet plane or outlet plane to change at least one property of the test gas at the test object. In some aspects, the at least one property includes test gas velocity, temperature, corresponding Mach number, and core flow uniformity.

In some aspects, the flexible body includes apertures between the plurality of flexible members that are movably interconnected together. Accordingly, the method can include injecting a barrier gas through the apertures into the flow path so as to form a barrier gas layer between the test gas and the flexible body. The barrier gas initially stays at the internal surface of the body but will dissipate into the test gas flow. However, the plurality of apertures down the length of the body provide for a barrier layer from the inlet to the outlet.

In some embodiments, the means for changing the shape of the flexible body includes at least one circumferential assembly that has at least one articulatable member that defines an aperture having an aperture plane with a variable area when articulated. Accordingly, the method can include passing the test gas from the outlet opening to have a first parameter profile. Then, the method can include articulating the at least one articulatable member to change the variable area of the aperture plane. The method can then include passing the test gas from the outlet opening to have a second parameter profile that is different from the first parameter profile in at least one parameter. That is, the nozzle changes the nature of the test gas, and operation of the nozzle to change the shape thereof changes the test gas profile going out the outlet.

In some embodiments, the method can include moving the throat plane relative to the inlet opening and outlet opening. The movement of the position of the throat plane can be performed with the longitudinal actuator as described herein. Other circumferential assemblies can also be moved longitudinally during operation of the wind tunnel in order to change the shape of the body of the CD nozzle. In some embodiments, the shape of the CD nozzle is varied to vary the area of at least the throat plane and the outlet plane, which can vary the area ratio between the nozzle and outlet areas.

In some embodiments, the configuration of the CD nozzle includes the elongate members that make up the body thereof. For this type of CD nozzle to hold its shape, and simultaneously have the ability to change the dimensions of the throat area and the exit area (in addition to the inlet area), there can be a structural accommodation of forces resulting from the pressure differential outside the nozzle body to those inside the nozzle flow path such that the area remains constant at each cross-sectional profile while airflow is being passed through the nozzle. The body can include the flexible members associated together in a cloth-like form to form the shape of the nozzle. The flexible members provide the CD nozzle body with an inherent flexibility. If the flexibility is such that the pressure differential can cause a range of motion in a joint or group of joints or influences the ability to move joints by moving the elongate member and therefore a resulting change in overall axial and/or radial dimensions, the flexibility can be stiff enough such that pressure changes do not result in causing deflections in the members. The flexibility is sufficient such that the range of motion appreciably changes the dimensions of the nozzle, but resilient enough to maintain the shape during use. The difference of pressures between the inside of the nozzle flow path and the exterior of the nozzle (e.g., in the cavity in the housing) can be balanced by an overall exterior pressure modulation to counter the internal pressure.

The body of the CD nozzle includes an inherent porosity formed by the apertures or slit apertures between adjacent flexible members of the nozzle body. The porosity from the outside to the inside of the nozzle flow path allows for an application of an exterior pressure of a barrier gas that can be utilized where it is desirable for the barrier gas to permeate to the inside of the nozzle into the flow path. The gas can provide a counter pressure to the test gas in the flow path, and also cause a secondary effect such as the cooling of the CD nozzle body. The layer of barrier gas provides a simulated smooth surface. That is, the gas provides a layer that simulates a smooth surface for the test gas passing through the nozzle flow path. The gas can function as a thin film boundary layer, but is composed of the barrier gas. While the surface of the flexible nozzle body can be rough, uneven, or have variations due to the different flexible elongate nozzle body members and intersections thereof and slit apertures formed thereby, the barrier gas passes through the slit apertures and forms the barrier gas layer to simulate a smooth internal surface on the flexible nozzle body.

In some embodiments, the configuration of the flexible elongate nozzle body members with the external pressurized barrier gas (e.g., higher pressure than within nozzle flow path) allows for cooling, such as transpiration. The external pressurization of the nozzle body can help hold the shape and provide the barrier gas to the external surface of the nozzle body and individual flexible elongate body members, between the flexible elongate body members, and into the flow path so as to be pushed against the internal surface of the nozzle body and individual body members. The barrier gas flow rate can be adjusted to inhibit the heat from the test gas from overheating or damaging the nozzle body or individual body members. Often, the barrier gas is nitrogen or other non-reactive gas that does not interact with the substances of the test gas, such as argon, helium, or the like.

In some embodiments, methods of operation include measuring mass flow through the nozzle and into the test area of the test cell. The mass flow can be from the test gas passing into the nozzle inlet and from the pressurized boundary gas that penetrates through the flexible nozzle body (e.g., between the nozzle body members). As a result, the mass of barrier gas being introduced into the nozzle flow path can be recorded for use in subsequent calculations. The mass of the barrier gas introduced into the nozzle flow path can be subtracted from the known mass of the test gas (e.g., mass flow rates).

One skilled in the art will appreciate that, for the processes and methods disclosed herein, the functions performed in the processes and methods may be implemented in differing order. Furthermore, the outlined steps and operations are only provided as examples, and some of the steps and operations may be optional, combined into fewer steps and operations, or expanded into additional steps and operations without detracting from the essence of the disclosed embodiments.

In one embodiment, the present methods can include aspects performed on a computing system. As such, the computing system can include a memory device that has the computer-executable instructions for performing the methods. The computer-executable instructions can be part of a computer program product that includes one or more algorithms for performing any of the methods of any of the claims.

In one embodiment, any of the operations, processes, or methods, described herein can be performed or cause to be performed in response to execution of computer-readable instructions stored on a computer-readable medium and executable by one or more processors. The computer-readable instructions can be executed by a processor of a wide range of computing systems from desktop computing systems, portable computing systems, tablet computing systems, hand-held computing systems, as well as network elements, and/or any other computing device. The computer readable medium is not transitory. The computer readable medium is a physical medium having the computer-readable instructions stored therein so as to be physically readable from the physical medium by the computer/processor.

There are various vehicles by which processes and/or systems and/or other technologies described herein can be effected (e.g., hardware, software, and/or firmware), and that the preferred vehicle may vary with the context in which the processes and/or systems and/or other technologies are deployed. For example, if an implementer determines that speed and accuracy are paramount, the implementer may opt for a mainly hardware and/or firmware vehicle; if flexibility is paramount, the implementer may opt for a mainly software implementation; or, yet again alternatively, the implementer may opt for some combination of hardware, software, and/or firmware.

The various operations described herein can be implemented, individually and/or collectively, by a wide range of hardware, software, firmware, or virtually any combination thereof. In one embodiment, several portions of the subject matter described herein may be implemented via application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), digital signal processors (DSPs), or other integrated formats. However, some aspects of the embodiments disclosed herein, in whole or in part, can be equivalently implemented in integrated circuits, as one or more computer programs running on one or more computers (e.g., as one or more programs running on one or more computer systems), as one or more programs running on one or more processors (e.g., as one or more programs running on one or more microprocessors), as firmware, or as virtually any combination thereof, and that designing the circuitry and/or writing the code for the software and/or firmware are possible in light of this disclosure. In addition, the mechanisms of the subject matter described herein are capable of being distributed as a program product in a variety of forms, and that an illustrative embodiment of the subject matter described herein applies regardless of the particular type of signal bearing medium used to actually carry out the distribution. Examples of a physical signal bearing medium include, but are not limited to, the following: a recordable type medium such as a floppy disk, a hard disk drive (HDD), a compact disc (CD), a digital versatile disc (DVD), a digital tape, a computer memory, or any other physical medium that is not transitory or a transmission. Examples of physical media having computer-readable instructions omit transitory or transmission type media such as a digital and/or an analog communication medium (e.g., a fiber optic cable, a waveguide, a wired communication link, a wireless communication link, etc.).

It is common to describe devices and/or processes in the fashion set forth herein, and thereafter use engineering practices to integrate such described devices and/or processes into data processing systems. That is, at least a portion of the devices and/or processes described herein can be integrated into a data processing system via a reasonable amount of experimentation. A typical data processing system generally includes one or more of a system unit housing, a video display device, a memory such as volatile and non-volatile memory, processors such as microprocessors and digital signal processors, computational entities such as operating systems, drivers, graphical user interfaces, and applications programs, one or more interaction devices, such as a touch pad or screen, and/or control systems, including feedback loops and control motors (e.g., feedback for sensing position and/or velocity; control motors for moving and/or adjusting components and/or quantities). A typical data processing system may be implemented utilizing any suitable commercially available components, such as those generally found in data computing/communication and/or network computing/communication systems.

The herein described subject matter sometimes illustrates different components contained within, or connected with, different other components. Such depicted architectures are merely exemplary, and that in fact, many other architectures can be implemented which achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively “associated” such that the desired functionality is achieved. Hence, any two components herein combined to achieve a particular functionality can be seen as “associated with” each other such that the desired functionality is achieved, irrespective of architectures or intermedial components. Likewise, any two components so associated can also be viewed as being “operably connected”, or “operably coupled”, to each other to achieve the desired functionality, and any two components capable of being so associated can also be viewed as being “operably couplable”, to each other to achieve the desired functionality. Specific examples of operably couplable include, but are not limited to: physically mateable and/or physically interacting components and/or wirelessly interactable and/or wirelessly interacting components and/or logically interacting and/or logically interactable components.

In various examples, the system can comprise a controller configured to control various parameters. For example, the controller can be in signal communication with the nitrous oxide source, pump, valve, inlet, chamber, accelerators, ports, or combinations thereof. For example, the controller can control the flow rate, pressure, and/or temperature of the nitrous oxide and nitrogen, independent of each other, as introduced into the chamber. The controller can control the temperature of nitrogen and/or a current to an ohmic heater. The controller can control a flow rate of the gaseous composition of nitrous oxide and nitrogen independent of each other. In various examples, the controller 118 comprises a processing unit operatively coupled to memory.

FIG. 6 shows an example computing device 600 (e.g., a computer) that may be arranged in some embodiments to perform the methods (or portions thereof) described herein. In a very basic configuration 602, computing device 600 generally includes one or more processors 604 and a system memory 606. A memory bus 608 may be used for communicating between processor 604 and system memory 606.

Depending on the desired configuration, processor 604 may be of any type including, but not limited to: a microprocessor (μP), a microcontroller (μC), a digital signal processor (DSP), or any combination thereof. Processor 604 may include one or more levels of caching, such as a level one cache 610 and a level two cache 612, a processor core 614, and registers 616. An example processor core 614 may include an arithmetic logic unit (ALU), a floating point unit (FPU), a digital signal processing core (DSP Core), or any combination thereof. An example memory controller 618 may also be used with processor 604, or in some implementations, memory controller 618 may be an internal part of processor 604.

Depending on the desired configuration, system memory 606 may be of any type including, but not limited to: volatile memory (such as RAM), non-volatile memory (such as ROM, flash memory, etc.), or any combination thereof. System memory 606 may include an operating system 620, one or more applications 622, and program data 624. Application 622 may include a determination application 626 that is arranged to perform the operations as described herein, including those described with respect to methods described herein. The determination application 626 can obtain data, such as pressure, flow rate, and/or temperature, and then determine a change to the system to change the pressure, flow rate, and/or temperature.

Computing device 600 may have additional features or functionality, and additional interfaces to facilitate communications between basic configuration 602 and any required devices and interfaces. For example, a bus/interface controller 630 may be used to facilitate communications between basic configuration 602 and one or more data storage devices 632 via a storage interface bus 634. Data storage devices 632 may be removable storage devices 636, non-removable storage devices 638, or a combination thereof. Examples of removable storage and non-removable storage devices include: magnetic disk devices such as flexible disk drives and hard-disk drives (HDD), optical disk drives such as compact disk (CD) drives or digital versatile disk (DVD) drives, solid state drives (SSD), and tape drives to name a few. Example computer storage media may include: volatile and non-volatile, removable and non-removable media implemented in any method or technology for storage of information, such as computer readable instructions, data structures, program modules, or other data.

System memory 606, removable storage devices 636 and non-removable storage devices 638 are examples of computer storage media. Computer storage media includes, but is not limited to: RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which may be used to store the desired information and which may be accessed by computing device 600. Any such computer storage media may be part of computing device 600.

Computing device 600 may also include an interface bus 640 for facilitating communication from various interface devices (e.g., output devices 642, peripheral interfaces 644, and communication devices 646) to basic configuration 602 via bus/interface controller 630. Example output devices 642 include a graphics processing unit 648 and an audio processing unit 650, which may be configured to communicate to various external devices such as a display or speakers via one or more A/V ports 652. Example peripheral interfaces 644 include a serial interface controller 654 or a parallel interface controller 656, which may be configured to communicate with external devices such as input devices (e.g., keyboard, mouse, pen, voice input device, touch input device, etc.) or other peripheral devices (e.g., printer, scanner, etc.) via one or more I/O ports 658. An example communication device 646 includes a network controller 660, which may be arranged to facilitate communications with one or more other computing devices 662 over a network communication link via one or more communication ports 664.

The network communication link may be one example of a communication media. Communication media may generally be embodied by computer readable instructions, data structures, program modules, or other data in a modulated data signal, such as a carrier wave or other transport mechanism, and may include any information delivery media. A “modulated data signal” may be a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. By way of example, and not limitation, communication media may include wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, radio frequency (RF), microwave, infrared (IR), and other wireless media. The term computer readable media as used herein may include both storage media and communication media.

Computing device 600 may be implemented as a portion of a small-form factor portable (or mobile) electronic device such as a cell phone, a personal data assistant (PDA), a personal media player device, a wireless web-watch device, a personal headset device, an application specific device, or a hybrid device that includes any of the above functions. Computing device 600 may also be implemented as a personal computer including both laptop computer and non-laptop computer configurations. The computing device 600 can also be any type of network computing device. The computing device 600 can also be an automated system as described herein.

The embodiments described herein may include the use of a special purpose or general-purpose computer including various computer hardware or software modules.

Embodiments within the scope of the present invention also include computer-readable media for carrying or having computer-executable instructions or data structures stored thereon. Such computer-readable media can be any available media that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to carry or store desired program code means in the form of computer-executable instructions or data structures and which can be accessed by a general purpose or special purpose computer. When information is transferred or provided over a network or another communications connection (either hardwired, wireless, or a combination of hardwired or wireless) to a computer, the computer properly views the connection as a computer-readable medium. Thus, any such connection is properly termed a computer-readable medium. Combinations of the above should also be included within the scope of computer-readable media.

Computer-executable instructions comprise, for example, instructions and data which cause a general purpose computer, special purpose computer, or special purpose processing device to perform a certain function or group of functions. Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

In some embodiments, a computer program product can include a non-transient, tangible memory device having computer-executable instructions that when executed by a processor, cause performance of a method that can include: providing a dataset having object data for an object and condition data for a condition; processing the object data of the dataset to obtain latent object data and latent object-condition data with an object encoder; processing the condition data of the dataset to obtain latent condition data and latent condition-object data with a condition encoder; processing the latent object data and the latent object-condition data to obtain generated object data with an object decoder; processing the latent condition data and latent condition-object data to obtain generated condition data with a condition decoder; comparing the latent object-condition data to the latent-condition data to determine a difference; processing the latent object data and latent condition data and one of the latent object-condition data or latent condition-object data with a discriminator to obtain a discriminator value; selecting a selected object from the generated object data based on the generated object data, generated condition data, and the difference between the latent object-condition data and latent condition-object data; and providing the selected object in a report with a recommendation for validation of a physical form of the object. The non-transient, tangible memory device may also have other executable instructions for any of the methods or method steps described herein. Also, the instructions may be instructions to perform a non-computing task, such as synthesis of a molecule and or an experimental protocol for validating the molecule. Other executable instructions may also be provided.

The present disclosure is not to be limited in terms of the particular embodiments described in this application, which are intended as illustrations of various aspects. Many modifications and variations can be made without departing from its spirit and scope, as will be apparent to those skilled in the art. Functionally equivalent methods and apparatuses within the scope of the disclosure, in addition to those enumerated herein, will be apparent to those skilled in the art from the foregoing descriptions. Such modifications and variations are intended to fall within the scope of the appended claims. The present disclosure is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled. It is to be understood that this disclosure is not limited to particular methods, reagents, compounds compositions or biological systems, which can, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting.

With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.

It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to embodiments containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.”

In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group.

As will be understood by one skilled in the art, for any and all purposes, such as in terms of providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges thereof. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range discussed herein can be readily broken down into a lower third, middle third and upper third, etc. As will also be understood by one skilled in the art all language such as “up to,” “at least,” and the like include the number recited and refer to ranges which can be subsequently broken down into subranges as discussed above. Finally, as will be understood by one skilled in the art, a range includes each individual member. Thus, for example, a group having 1-3 cells refers to groups having 1, 2, or 3 cells. Similarly, a group having 1-5 cells refers to groups having 1, 2, 3, 4, or 5 cells, and so forth.

From the foregoing, it will be appreciated that various embodiments of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the present disclosure. Accordingly, the various embodiments disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

All references recited herein are incorporated herein by specific reference in their entirety, especially the subject matter relating to CD nozzles, and the systems and operating environments thereof.

References: WO 2020/210179; U.S. Pat. Nos. 6,606,851; 6,779,335; 8,459,036; 9,470,603; 9,598,323; 10,738,735; “Modeling of N2O Decomposition Events” by Arif Karabeyoglu, Jonny Dyer, Jose Stevens, and Brian Cantwell. 44th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit, Joint Propulsion Conferences. 

1. A method for nitrous decomposition, comprising: expanding liquid nitrous into gaseous nitrous in a decomposition chamber; injecting heated nitrogen gas into the decomposition chamber so as to heat the gaseous nitrous, wherein the heated nitrogen gas is at a nitrous decomposition temperature; heating the gaseous nitrous with the heated nitrogen gas to the nitrous decomposition temperature; and decomposing the gaseous nitrous into nitrogen and oxygen.
 2. The method of claim 1, further comprising heating the nitrogen to at least the nitrous decomposition temperature, which is at least about 900 degrees K.
 3. The method of claim 1, further comprising heating the liquid nitrous prior to expansion into the decomposition chamber.
 4. The method of claim 1, further comprising performing the decomposition without a catalyst or heating element in the decomposition chamber.
 5. The method of claim 1, further comprising mixing the gaseous nitrous and heated nitrogen gas in the decomposition chamber with a mixing apparatus.
 6. The method of claim 1, further comprising swirling the gaseous nitrous and heated nitrogen gas together with a swirling device.
 7. The method of claim 6, further comprising passing the heated nitrogen gas through a swirling device to cause the heated nitrogen gas to swirl with the nitrous gas.
 8. The method of claim 7, further comprising passing the liquid nitrous through a swirling nozzle for expanding the liquid nitrous into the gaseous nitrous to cause the gaseous nitrous to swirl with the heated nitrogen gas.
 9. A nitrous decomposition system comprising: a liquid nitrous supply system; a heated nitrogen supply system configured to provide heated nitrogen gas at a nitrous decomposition temperature; and a decomposition reactor comprising: a decomposition chamber having an outlet; a liquid nitrous nozzle configured to expand the liquid nitrous into gaseous nitrous in the decomposition chamber; and a heated nitrogen nozzle configured to inject heated nitrogen gas into the decomposition chamber so as to mix with the gaseous nitrous, wherein the decomposition reactor is configured to: heat the gaseous nitrous with the heated nitrogen gas to the nitrous decomposition temperature; and decompose the gaseous nitrous into nitrogen and oxygen.
 10. The system of claim 9, wherein the heated nitrogen system includes at least one heater for heating the nitrogen to at least the nitrous decomposition temperature, which is at least about 1300 degrees K.
 11. The system of claim 9, wherein the liquid nitrous supply system includes at least one heater for heating the liquid nitrous prior to expansion into the decomposition chamber.
 12. The system of claim 9, wherein the decomposition chamber is devoid of a catalyst or heating element therein.
 13. The system of claim 9, further comprising a mixing device configured for mixing the gaseous nitrous and heated nitrogen gas in the decomposition chamber.
 14. The system of claim 9, further comprising a swirling device configured for swirling the gaseous nitrous and heated nitrogen gas together.
 15. The system of claim 14, wherein the swirling device is positioned at an inlet to the decomposition chamber, such that the heated nitrogen gas is passed through the swirling device to cause the heated nitrogen gas to swirl with the nitrous gas.
 16. The system of claim 15, further comprising a swirling nozzle positioned at an inlet to the decomposition chamber, such that the liquid nitrous is passed through the swirling nozzle for expanding the liquid nitrous into the gaseous nitrous to cause the gaseous nitrous to swirl with the heated nitrogen gas.
 17. A wind tunnel system comprising: the nitrous decomposition system of claim 9; and a variable converging-diverging nozzle having an inlet that is fluidly coupled with the outlet of the decomposition chamber.
 18. A wind tunnel system comprising: the nitrous decomposition system of claim 14; and a variable converging-diverging nozzle having an inlet that is fluidly coupled with the outlet of the decomposition chamber.
 19. A wind tunnel system comprising: the nitrous decomposition system of claim 16; and a variable converging-diverging nozzle having an inlet that is fluidly coupled with the outlet of the decomposition chamber.
 20. A method for operating a wind tunnel, comprising: expanding liquid nitrous into gaseous nitrous in a decomposition chamber; injecting heated nitrogen gas into the decomposition chamber, wherein the heated nitrogen gas is at a nitrous decomposition temperature; heating the gaseous nitrous with the heated nitrogen gas to the nitrous decomposition temperature; decomposing the gaseous nitrous into nitrogen and oxygen as simulated air; and passing the simulated air through a nozzle into a wind tunnel containing a test object that receives the simulated air. 